From the Boutique:

Charging System Troubleshooting

by Chris Hajer

conrad davis wrote...

> The battery is not charging

How do you know?

> and if I disconnect it while the bike is running it stops so I assume the alternator is not working.

Wrong. Your 883 is not a car. It should die when you disconnect the cable.

> I've checked the winding resistance at the v/reg connector and it seems ok.

What does 'seems ok' mean? It's either within spec, or it's not.

> Are the any other checks I can do before I take the engine apart??

YES...RTFM! The charging system is not complicated on a Harley, but you should check it in the order suggested in the manual. Since yours is an 883, I'll assume it's 1986 or later. The 4 speeds and 5 speeds have slightly different specs, but general procedures are the same for all the alternator equipped models. You'll need an ac/dc volt meter at least, and an ohm meter. A load tester and some other tools are nice to have too.

1. Check battery voltage and specific gravity. If you can't do that, you shouldn't be working on your charging system. If the battery is not fully charged, charge it or replace it with a known good one, at least temporarily. Perform a load test on the battery. If you can't do that, make sure the battery is fully charged and have a shop load test it for you. Have the load set at 57 amps for 15 seconds. The battery is good if it maintains 9.6 dcv or better at the end of the 15 seconds. Now you have to recharge the battery before you go any further.

2. With the battery back in the bike, fully charged, check the voltage. It should be 12.6 to 12.8 dcv. This is for the older (pre 97) batteries that have fluid caps. The newer batteries that are sealed are considered fully charged when they have 13.0 dcv.

3. Did the battery terminal spark at all when you connected the battery cables? If so, and the key switch is off, you've got a static drain while the bike is sitting idle. I won't go into detail on how to find it, but basically a component is drawing current when everything should be turned off. You're not leaving the key in the acc position accidentally, right? You can have a static drain even if there's no spark, but a significant drain will create a small spark when you make the final battery connection (not a good thing if your freshly charged battery is still emitting hydrogen gas. BOOM!)

4. Turn on the lights, and apply the brakes, but don't start the bike. What is the battery voltage now? It should not be more than one volt less than it was with everything off. That's a poor man's load test. Not in the manual, just tossed it in for free.

5. Start the bike and run it at 2,000 rpm, or a very fast idle if you have no tach. What is the dcv at the battery now? It should be 13.5 - 14.5 dcv at 2,000 rpm. If not, you've got a charging problem. Since you have verified that the battery is ok in the previous steps, you know there's a component problem on the bike. It may be an actual component, or it may be the wiring between components, but it's not the battery. Wiring is a component too, but most people don't think of it that way. They think, regulator, stator, rotor, battery.

6. I'll skip the amp output test since most people don't have the instruments to measure more than 10 dc amps, in conjunction with a variable load to apply to the battery to maintain a constant 13.0 dcv during the amp test. That's not to say the amp output shouldn't be done...

7. Check the regulator ground. From the regulator case to the battery negative terminal should be less than 1 ohm. If not, clean the grounds and start over.

8. Check the resistance of the stator windings. Sounds like you did that. Use the specs in the manual for your bike. Also check for a stator that's shorted to ground. It would suck for the alternator to be making good acv, but sending it all straight to ground. If you find a problem with the resistance in the windings, or you have a short to ground, it's time to remove the primary cover and take a closer look.

9. Check the ac output from the stator. If you've got ac output, and the regulator is properly grounded, and you've got a good battery, and the connections are all good, then you've got a bad regulator. The stator/rotor (referred to as an alternator) are putting out ac voltage, but the regulator is not properly converting it to dc, or it's converting it properly, but is shunting it to ground, or the regulator is internally open. In any case, the regulator is NFG. Get a new one installed and start over.

10. That's about it, I think. This was from memory; the manual should have a better description of all the tests. Don't think I skipped any...

Chris Hajer ('88 XL, with it's share of charging system problems over the past 10 years: magnets falling off the rotor and trashing the stator, bad regulator, bad main circuit breaker, battery shorted internally, battery with no water in it (how'd that happen?), and a busted wire between the main circuit breaker and the battery.)